Near midnight, the mini-sub returned to its host submarine. Though unheard of elsewhere in the Navy at the time, such operations had been routine aboard USS Grayback (SS-574) for more than a decade. On this evening, Jan. 16, 1982, the submarine had bottomed off the coast of the Republic of the Philippines. Divers soon secured the mini-sub, or SEAL delivery vehicle (SDV), within the submarine's starboard hangar. No one knew that tragedy lay just ahead.
July 6, 1988, Piper Oilfield, North Sea: As shifts changed and the night crew aboard Piper Alpha assumed duties for the evening, one of the platform?s two condensate pumps failed. The crew worked to resolve the issue before platform production was affected. But unknown to the night shift, the failure occurred just hours after a critical pressure safety valve had just been removed from the other condensate pump system and was temporarily replaced with a hand-tightened blind flange. As the night crew turned on the alternate condensate pump system, the blind flange failed under the high pressure, resulting in a chain reaction of explosions and failures across Piper Alpha that killed 167 workers in the deadliest offshore oil industry disaster to date.